Re: How to Kill the Worker Thread ? - C / C++ / MFC Discussion Boards

Rajesh R Subramanian14-Apr-09 1:43

14-Apr-09 1:43

I know, but I'm ignoring that.

I've been balancing the votes. Forget it, the votes will be balanced by the regulars.

Smile | :)

It is a crappy thing, but it's life -^ Carlo Pallini

Re: How to Kill the Worker Thread ? [modified]

ParagPatel14-Apr-09 0:27

ParagPatel

14-Apr-09 0:27

Can you paste your code snap here?

You can also use flag mechanism, its good solution.

//globle variable
HANDLE hr1,hr2;
bool stopTh; //default set to false.



void CThreadDemoDlg::OnStart() 
{
	// TODO: Add your control notification handler code here

	stopTh = false;

	hr1 = CreateThread(NULL,0,(unsigned long (__stdcall *)(void *))WorkerThreadOne,this,0,0);
	hr2 = CreateThread(NULL,0,(unsigned long (__stdcall *)(void *))WorkerThreadTwo,this,0,0);
}
void CThreadDemoDlg::OnEnd() 
{
	// TODO: Add your control notification handler code here

	stopTh = true;
}

UINT WorkerThreadOne(LPVOID Param)
{
	fstream OutFile;
	OutFile.open("FileOne.txt",ios::out);

	for(int i=0;i<10000;i++)
	{
		if(stopTh == true)
			break;
		OutFile  << i << " ";
	}
	OutFile.close();
	return true;
}

Why 1.0/5.0?

Parag Patel

modified on Thursday, April 16, 2009 9:40 AM

Re: How to Kill the Worker Thread ?

David Crow14-Apr-09 3:02

David Crow

14-Apr-09 3:02

ParagPatel wrote:
if(stopTh == true)

Unless stopTh is volatile, the compiler will optimize out this check.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Re: How to Kill the Worker Thread ?

ParagPatel14-Apr-09 3:56

ParagPatel

14-Apr-09 3:56

Thanks ,
Yes.. stopTH must be globle or thread function must use through passed class object.

Parag Patel
Sr. Software Eng, Varaha Systems

Re: How to Kill the Worker Thread ?

David Crow14-Apr-09 3:58

David Crow

14-Apr-09 3:58

ParagPatel wrote:
Thanks Simmons,

ParagPatel wrote:
Yes.. stopTH must be globle

Being global has nothing to do with it. If the compiler detects that nothing in the loop is changing that variable, it will optimize out the check. So even if the secondary thread changes that variable, it will go unseen.

Re: How to Kill the Worker Thread ?

Rajesh R Subramanian14-Apr-09 4:28

Rajesh R Subramanian

14-Apr-09 4:28

Changing it through the class object = changing it from a different thread (the main thread of the app). Which means it will be optimized away.

It is a crappy thing, but it's life -^ Carlo Pallini

Re: How to Kill the Worker Thread ?

Hamid_RT13-Apr-09 23:40

Hamid_RT

13-Apr-09 23:40

Did you see bottom of CreateThread on the MSDN it explains it for you.

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Re: How to Kill the Worker Thread ?

David Crow14-Apr-09 2:55

David Crow

14-Apr-09 2:55

Suresh H wrote:
for(int i=0;i<10000;i++)

You need to add another condition to this loop, something like:

CEvent m_event; // start as non-signaled
 
for (int i = 0; i < 10000; i++)
{
    // set the event to signaled when the End button is clicked
    if (WaitForSingleObject(m_event.m_hObject, 0) == WAIT_OBJECT_0)
        break;
}

using database in project

sunny_vc13-Apr-09 22:51

sunny_vc

13-Apr-09 22:51

Hi all,
I have to work on a small project in VC++ using "Visual Studio.net 2003".
I have to use data base in my project.
Do I need to install anything to use ODBC or is it built in.
If yes, please tell met the softwares that are to be installed to use database.

Regards,
Sunil Kumar

Re: using database in project

_AnsHUMAN_ 13-Apr-09 22:57

_AnsHUMAN_

13-Apr-09 22:57

See ODBC[^]

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

How to update the title bar of a window with C & Win32 APIs only?

mr2_9313-Apr-09 22:48

mr2_93

13-Apr-09 22:48

Hi all,

I am trying to write a lightweight Windows utility with C & Win32 APIs only.

I have setup a timer and would like to display some information on the window title bar (not dialog box) at a set time interval.

I tried to use the SetWindowText function but it doesn't seem to work.

Any help or pointers would be appreciated! Thanks.

M.

Re: How to update the title bar of a window with C & Win32 APIs only?

Hamid_RT13-Apr-09 23:46

Hamid_RT

13-Apr-09 23:46

Did you use of SetWindowText on WM_TIMER?

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Re: How to update the title bar of a window with C & Win32 APIs only?

mr2_9313-Apr-09 23:59

mr2_93

13-Apr-09 23:59

Thank you. That was the problem. It works now.

The background window of CMainFrame

prithaa13-Apr-09 22:29

prithaa

13-Apr-09 22:29

Hello,

I have a CMDIChildWnd which has CRichEditCtrl window over it.Now there are 4 windows of CRichEditCtrl on CMDIChildWnd.

When these CRichEditCrl windows appear on the CMDIChildWnd the background color of CMDIChildWNd changes or sometimes whatever is in the background of the window is seen on the window.

This problem is not on my PC but when i transfer my .exe on another PC then there is a problem

Prithaa

Re: The background window of CMainFrame

Iain Clarke, Warrior Programmer14-Apr-09 3:38

Iain Clarke, Warrior Programmer

14-Apr-09 3:38

I'm not sure what your problem is, but in general you should not create windows directly on CMDIChildWnd. Try making your own view class inheriting from CRichEditView, and then put then in the CChildFrame using splitters. There are plenty of resources searchable on CSplitterWnd, including loads on CP.

If you do things in a standard way, it increases their chances of working. I break the rules too, but you need to do it with your eyes open, and only if you can't avoid it.

Good luck,

Iain.

In the process of moving to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), give me a job!

Re: The background window of CMainFrame

prithaa14-Apr-09 17:44

prithaa

14-Apr-09 17:44

Hello,

Thanks for your reply.
Your explanation was very useful.
Let me try to explain the problem.

I have a project without Doc-View Architecture and the child window is created typically with the CreateNewChild().

Now I have a CView derived class and the OnDraw of this CView class displays text on the child window.

Also the CRichEditCtrl is displayed on the screen. This works fine with my PC.

But when I transfer the application it doesnt work. On the other PC when the childwindow opens it opens properly but when the window is resized the childwindow displays the contents that are there on the background of the child window.

For now lets forget CRichEditCtrl.

When I resize the childwindow should special care be taken to redraw the background of the window and I have not done that.

Any ideas of the problem.
Thanks
Prithaa

Re: The background window of CMainFrame

Iain Clarke, Warrior Programmer14-Apr-09 21:46

Iain Clarke, Warrior Programmer

14-Apr-09 21:46

There are user settings like redraw-window-when-dragging that may be different from pc-pc, and from user-user, so it's perfectly possible to see differing behaviour.

Are you handling WM_ERASEBKGND in your view?

Have you done anything strange in PreCreateWindow to change the WNDCLASS of the view to use a NULL brush?

Can you make a brand new project, and in the new view's OnDraw, do the following:

void CMyNewView::OnDraw (CDC *dc)
{
   CRect rc;
   GetClientRect (&rc);

   dc->FillSolidRect (&rc, RGB(255,0,0));
   dc->MoveTo (rc.TopLeft ());
   dc->LineTo (rc.BottonRight ());
}

This is from memory, so you many need the odd change. But this should made a solid red view, with a line from one corner to the other.

If this works (and it had better!) on both PCs, then you are doing something "clever" that is breaking it in your application. Just comment out loads of code, see when things start working, and work your way forward again.

Iain.

In the process of moving to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), give me a job! http://cv.imcsoft.co.uk/[^]

Re: The background window of CMainFrame

prithaa14-Apr-09 23:11

prithaa

14-Apr-09 23:11

Hello,

Thanks for this wonderful insight.I ll check all your points.

Prithaa

How to add Event handler to dynamically created Button

hemlat13-Apr-09 21:34

hemlat

13-Apr-09 21:34

Hi,
I have created Button on my Dialog Box using following code.

CButton *m_myButton;
m_myButton = new CButton();
m_myButton->Create(_T("My button"), WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON, 
				CRect(800,y1,900,(y1+25)),this, 1);

How should I add Event handler to this button.

Re: How to add Event handler to dynamically created Button

fitatc13-Apr-09 21:38

fitatc

13-Apr-09 21:38

I think you can use CMyButton instead of CButton:

class CMyButton: public CButton{
};

you can add Event handler(massage handler) to this class.

Re: How to add Event handler to dynamically created Button

Hamid_RT13-Apr-09 23:47

Hamid_RT

13-Apr-09 23:47

Do I need to insert a class for an event?no.

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Re: How to add Event handler to dynamically created Button [modified]

_AnsHUMAN_ 13-Apr-09 21:38

_AnsHUMAN_

13-Apr-09 21:38

one easy way is to create a button at design time, and double click on it to add the handler to know what all is needed..
Otherwise also, it is not a mammoth task. You have to declare a function, define it and add an entry for the button click to the message map.

Also you may be interested ON_CONTROL_RANGE

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

modified on Tuesday, April 14, 2009 4:02 AM

Re: How to add Event handler to dynamically created Button

hemlat13-Apr-09 23:05

hemlat

13-Apr-09 23:05

thanks for your reply.I have declared one function.I have added entry in message map.
It is working for me.

Re: How to add Event handler to dynamically created Button

Hamid_RT13-Apr-09 23:54

Hamid_RT

13-Apr-09 23:54

You can insert this code on your code and then if you want you can make your button.
#define IDC_DYNAMICBUTTON 3000

BEGIN_MESSAGE_MAP(CMFCDlg, CDialog)
ON_BN_CLICKED(IDC_DYNAMICBUTTON,&CMFCDlg::OnBnClickedbutton)
END_MESSAGE_MAP()

void CMFCDlg::OnBnClickedbutton()
{
}

//header file
public:
afx_msg void OnBnClickedbutton();

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

How do I catch the 0xC0000005 Exception?

mildred-frontfree13-Apr-09 21:33

mildred-frontfree

13-Apr-09 21:33

I need to catch the 0xC0000005 Exception in my code. I've tried try{}catch(CException *e){}, but it didn't work.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.